The present invention relates to a control device. More particularly this invention concerns a magnetic-type lock.
A magnetic-type lock is known wherein the key carries one or more magnets which coact with magnetic tumblers or the like in the cylinder of the lock in order to allow this cylinder to rotate relative to its housing. Such locks have several disadvantages. First of all it is relatively common for the magnetic tumblers, which must be relatively loose in order to be magnetically displaceable, to become jammed in the lock. Furthermore in such systems it is almost always possible to pull out the key when the cylinder is twisted relative to the housing so that a frequent occurrence is that the lock is accidentally left unlocked.
Another disadvantage of the known magnetic-type locks is that the variations in coding are relatively limited. Thus the pick resistance which such locks are known for is in part counterbalanced by the fact that only a relatively small number of different lock combinations are possible.